Why is there a minimum average interval on AWAC?

During the current profile the pressure is measured and estimates of minimum, maximum, and mean values are recorded. The minimum length (Average Interval) current profile is 55 seconds. If you are curious, you can find these values logged in the "Wave Header File" (*.WHD). These values are important because we use them to define where the measurement volumes will start and how large they will be. This is true for both the velocity and AST measurements. When measuring waves by using AST at the same time there are velocity measurements in one big cell - so not in a profile - that are needed for measurements of orbital velocities. You can see this in the "Deployment Planning" of the software under Wave - static mode "Velocity cell size".

In addition to this, we also perform an SNR check on the acoustic signal of the current profile and make sure that the wave measurement cells are not positioned at a range where the acoustic signal is poor. If the SNR is too low for the position based on the pressure then we move them closer to the AWAC until the SNR is acceptable. This is particularly important for locations that have very clear water.